A diagnostic method to identify a leak in a simulator valve for a vehicle brake system comprising the steps of: (1) energizing a secondary three-way valve, a pumping valve, a simulator test valve, and a plurality of apply valves in order to maintain a pressure medium from a plunger assembly within a boost circuit; (2) applying a plunger in the plunger assembly to a predetermined pressure level; (3) holding the plunger in position within the plunger assembly; and (4) identifying a leak in a simulator valve via a signal from an ECU to a vehicle user interface if the pressure in the boost circuit deteriorates at or more than a pre-determined rate.
Legal claims defining the scope of protection, as filed with the USPTO.
2. The diagnostic method as defined in claim 1 wherein a reservoir for providing the pressure medium to the brake system is disposed in a first module while the simulator test valve is disposed in a second module separate from the first module.
3. The diagnostic method as defined in claim 2 wherein a boost pressure sensor is used to measure pressure in the boost circuit.
4. The diagnostic method as defined in claim 2 wherein the plunger applies pressure to the boost circuit upon actuation of a motor in the plunger assembly via an electronic control unit.
5. The diagnostic method as defined in claim 2 wherein a pressure sensor in the boost circuit measures the rate of pressure deterioration in the boost circuit.
6. The diagnostic method as defined in claim 2 wherein the step of energizing the plurality of apply valves prevents pressure medium from flowing from plurality of apply valves toward a corresponding plurality of dump valves, and energizing the simulation test valve blocks the flow of fluid or pressure medium in the direction from a simulation chamber of a pedal simulator in the second module to a first output pressure chamber of a master cylinder in the first module.
7. The diagnostic method as defined in claim 6 wherein the step of energizing the pumping valve enables the uni-directional flow of the medium to flow from the plunger assembly into the boost circuit.
10. The diagnostic method as defined in claim 9 wherein a reservoir for providing the medium to the brake system is disposed in a first module while the simulator test valve is disposed in a second module separate from the first module.
11. The diagnostic method as defined in claim 10 wherein a pressure sensor in the boost circuit measures the rate of pressure deterioration in the boost circuit.
12. The diagnostic method as defined in claim 10 wherein the pre-determined distance falls in the range of about 5 mm to about 20 mm.
13. The diagnostic method as defined in claim 10 wherein the plunger applies pressure to the boost circuit upon actuation of a motor in the plunger assembly via an electronic control unit.
14. The diagnostic method as defined in claim 10 wherein the step of energizing the plurality of apply valves prevents pressure medium from flowing from plurality of apply valves toward a corresponding plurality of dump valves, and energizing the simulation test valve blocks the flow of pressure medium in the direction from a simulation chamber of a pedal simulator in the second module to a first output pressure chamber of a master cylinder in the first module.
15. The diagnostic method as defined in claim 14 wherein the step of energizing the pumping valve enables the uni-directional flow of the pressure medium from the plunger assembly into the boost circuit.
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November 19, 2019
September 20, 2022
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